Dopamine biosensor with metal oxide nanoparticles decorated multi-walled carbon nanotubes

Efficient electrochemical biosensors were fabricated using metal oxide nanoparticle-coated multi-walled carbon nanotubes (MWNTs) and tested for the selective detection of dopamine (DA). MWNTs were synthesised by chemical vapour deposition (CVD) technique by pyrolysis of acetylene over hydrogen-decrepitated mischmetal-based AB3 alloy hydride catalyst. Functionalised MWNTs were decorated with SnO2 and ZnO nanoparticles by simple chemical treatment. As-prepared samples were characterised by SEM, TEM, FTIR and EDX analyses. DA biosensor electrodes were fabricated using glassy carbon electrodes (GCE) decorated with MWNTs, SnO2/MWNTs and ZnO/MWNTs and their electrochemical properties were investigated by cyclic voltammograms (CV). The results indicate that ZnO/MWNT-based DA biosensor has the best sensing performance with linear range of detection up to 300 µM, detection limit of 1 µM and sensitivity 785 nA/µM with excellent anti-interference ability from ascorbic acid and good stability.